PSI - Issue 17

Michał Kwietniewski et al. / Procedia Structural Integrity 17 (2019) 154 – 161 Michał Kwietniewski / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 1. Tensile behaviour for material with: (a) positive; ( b) negative Poisson’s ratio ; Mohamed et al. (2016).

Fig. 2. Negative Poisson’s ratio structures ; Imbalzano et al. (2018), Ma et al. (2010).

reinforcement structures provides this composition with a negative Poisson’s ratio (Fig. 2). It is also possible to develop such structures from already existing auxetic subassemblies, such as auxetic textiles. In comparison to conventional textile reinforced composites, the auxetic reinforced ones have a lot of advantages, such as higher shear resistance, better crack resistance and better damping properties. The proposed composite will have the elastomeric matrix reinforced with auxetic textile made of Helical Auxetic Yarn (HAY). The structure and the principle of operation of such textile were presented in Fig. 3. On the base of this principle it can be noticed that the essence of creating functional auxetic composites is the selection of a suitable matrix material. It determines the correct work of the HAY.

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Fig. 3. Helical Auxetic Yarn behaviour: (a) single yarn; (b) stretched single yarn; (c) set of yearns; (d) stretched set of yarns; Teik-Cheng (2015).

The review of elastomeric materials and the influence of their internal structure to solve the problem of correct selection of the matrix parameters for the fabrics reinforced composite is presented in the paper. This matrix is usually made of elastomer or resin with a relatively low hardness to allow proper work of auxetic woven Miller et al. (2009). The interaction of layers of auxetic fabrics with the composite matrix, which positions the HAY woven and transfers the stresses resulting from the work of the auxetics filaments can be found in Miller et